help!

I have a situation I’ve never been in before, so I’d appreciate any suggestions🙏🏻

I followed someone who was a speaker at an event at my company. I was actually supposed to volunteer that day, but I had an appointment, so I never ended up meeting him in person.

He has a private Instagram account. He followed me back pretty quickly, but he didn’t accept my follow request. Then a couple hours later, he sent me a message asking if we had ever met.

I’m wondering what I should respond with, or if I should respond at all?